Wednesday, August 22, 2007

Taping and Mudding Sheetrock

How to Tape and Mud Sheetrock

By Mark J. Donovan

Taping and mudding sheetrock involves some artistry and craftsmanship. However, most do it yourself homeowners can tape and mud a small sheetrock project with the right knowledge and tool set.

Proper Installation of Sheetrock

It is imperative that the sheetrock be hung properly in order to do a quality taping and mudding sheetrock job.

Sheetrock should be first installed on the ceiling.

After the ceiling has been sheetrocked, you can then move on to the wall. You should start at the top of the walls, by hanging an upper row of sheetrock.

After the first row of sheetrock has been hung on the walls you can then install the second row. It is important that the sheetrock seams be minimized to help ensure a quality finished wall look.

It is also important that the tapered ends of the sheetrock butt up against each other so that they create a slight depression line at approximately half way up the sheetrocked wall. This depression, or recessed area, enables the tape and mud to be applied over the joint seam so as to not create a significant bulge on the sheetrocked wall.

Taping and Mudding Sheetrock

Apply the First Coat of Mud

If you are using sheetrock paper tape, first apply a skim coat of mud, also known as joint compound, over the joint seams before applying the tape.

If you are using the fiberglass sheetrock tape with a sticky backing, you can apply it directly to the sheetrock seams and joints.

Once you have applied the sheetrock tape to the seam or joint, apply a thin skim coat of joint compound over the tape and seam/joint. Use a 6” broad knife to apply the joint compound and run it down the tapeline with long continuous smooth strokes. Do not run the knife perpendicular to the seam or joint with many short strokes. Otherwise you will create many vertical lines that will need to be sanded out. Once you have applied the first coat of joint compound let it dry.

Apply Second Coat of Mud

After the first coat has dried, use a 10” wide broad knife and apply a liberal amount of joint compound along the length of the seam or joint. Again, make long smooth strokes with the broad knife that run parallel to the seam.

When applying the second coat of joint compound, angle the blade slightly such that there is more joint compound left near the center of the seam. Ultimately you want to build up the seam/joint area with a little extra joint compound to fully cover the tape.

Note that this second coat of joint compound should spread out over the seam such that it is approximately 10 inches in width.

Again let this second application of joint compound dry. Usually it will take about 24 hours for it to dry.

Application of Third Coat of Mud

Before applying the third coat of joint compound use your 6” knife to knock off high spots on the sheetrock seam.

Now apply a final skim coat of joint compound over the seam, again feathering out the seam slightly wider than the previous application of joint compound. The purpose of this coat is fill in any miniscule cracks or lines in the existing sheetrock mud seam and to flare the seam out a little more.

Again let this third coat of joint compound dry over night.

Applying Mud to Corners

You may want to purchase Inside and Outside Corner trowels to help in taping and mudding corners. Corners can be a trick and it is where the real artistry comes into play. I would suggest starting in a closet for doing corners to get some experience on areas that will not be seen.

Applying Mud to Nail Holes

As with the seams, apply 3 coats of joint compound to the nail / screw holes. No tape is required for the nail holes.

With each new layer of joint compound, feather out the sheetrock patch so that after the 3rd coat the nail hole is covered with approximately a 6” wide circle of joint compound.

Note that you can apply the mud to the nail holes in parallel with the taping and mudding of seams.

Sanding Joints and Seams

The use of a sheetrock pole sander will produce the best finished drywall look, as well as save you significant time in sanding the joints and seams. I highly recommend the use of one. They are relatively cheap and well worth the investment. A pole sander is about 4-5 feet long and has a flexible 3.25”x9” head on it that you apply sheetrock mesh sheets to. You can also use a sheetrock hand sander as well.

When sanding the joints and seams make long smooth strokes with the pole or hand sander that run parallel to the seam. Apply less pressure to the middle of the seam and more toward the edges to feather out the edge of the joint seam.

It is important that you sand the edges of the seam so that they completely feather out to a smooth finish with the sheetrock. As you near the edges of the seam, you can turn the angle of your pole sander such that it is on a 45o angle.

Priming and Painting the Walls

With the sanding of the seams and joints complete, wipe down the walls with a damp rag to remove the sheetrock mud dust.

Next apply a coat of primer.

Finally apply two coats of paint, and your ready for trimming out the room.